Architectural Overview of SAP Host Agent

Executables and Services

The executable directory of SAP Host Agent is in the following location:

UNIX	/usr/sap/hostctrl/exe
Windows	%ProgramFiles%\SAP\hostctrl\exe
IBM i	/usr/sap/hostctrl/exe and objects in library R3SAP400

SAP Host Agent has the following executable programs and services:

The SAPHostExec service	saphostexec is a service or daemon that only runs under privileged user accounts such as root on UNIX or Local System under Windows. saphostexec hosts the life-cycle management processes of the SAP Host Agent itself, such as upgrade and installation.
The sapstartsrv service SAPHostControl	SAPHostControl runs within SAP Host Agent under the sapadm user. SAPHostControl should not be confused with sapstartsrv which runs under the `<sapsid>`adm user in the SAP system instance with the instance profile. Note SAPHostControl contains the functionality of the previous CCMS agent SAPCCMSR, that is, the agent that monitors hosts. For more information, see Central Monitoring with SAP NetWeaver Management Agents in the SAP NetWeaver Application Server for ABAP (AS ABAP) documentation.
The operating system collector saposcol	saposcol is a stand-alone program that runs in the operating system background. It runs independently of SAP instances exactly once per monitored host. saposcol collects data about operating system resources, including: Usage of virtual and physical memory CPU utilization Utilization of physical disks and file systems Resource usage of running processes saposcol makes the data available using a segment of the shared memory for various applications and all SAP instances on a host.
The DB4STATS program and command (IBM i only )	The DB4STATS program and command are partly contained in the R3SAP400 library. They provide the SAP Database Performance Collector for IBM i. You can find a detailed description of this collector in SAP Note 1622665 and in the documentation attached to this SAP Note.
The SAP ILE daemon (IBM i only )	The SAP ILE daemon is needed to update ILE components (objects in libraries) from the patch archive after installing a SAP kernel patch. You can find a detailed description of the SAP ILE daemon in SAP Note 1637588 .

Note

The installed programs are started automatically when the host is booted.

Windows	On Windows hosts, this is done by the services SAPHostControl and SAPHostExec.
UNIX	On UNIX the automatic start is ensured by the startup script sapinit.
IBM i	On IBM i, the programs are started by the auto-start job entry SAPINIT in subsystem QUSRWRK, which was created during the installation.

Profile File

The profile parameters of SAP Host Agent are stored in the host_profile file. This file is located in the executable directory of the SAP Host Agent (see Executables and Services above).

Working Directory

The working directory of SAP Host Agent is in the following location:

UNIX, IBM i	/usr/sap/hostctrl/work
Windows	%ProgramFiles%\SAP\hostctrl\work

The working directory contains, among other things, the following configuration files:

CSMCONF	Start file for the agents that contains connection data for the central monitoring system
SAPCCMSR.INI	Contains information about the extent to which plug-ins, log files, and SAPOSCOL information should be considered; this file is read when the agent is started. For more information, see Parameters of the SAPCCMSR.INI Configuration File in the SAP NetWeaver Application Server for ABAP (AS ABAP) documentation.

In an ABAP system, you can display all files in the working directory of SAP Host Agent in the central monitoring system. You can use transaction RZ21 to do this. In the Topology group box, select one of the Agents for ... radio buttons. The Monitoring: Display Technical Topology screen appears. Now select SAP Host Agent and then choose Working Directory of the Agent. The system displays the files of the directory. To display the contents of a file, choose the file by double-clicking it.

Log Files

The following log files are created during runtime for SAP Host Agent. They are available in the working directory of SAP Host Agent:

sapstartsrv_ccms.log	This log file is for central monitoring. It is stored in subdirectory sapccmsr of the working directory.
sapstartsrv.log	Contains the developer trace for sapstartsrv
dev_saphostexec	Contains the developer trace for saphostexec.
dev_sapdbctrl	Contains the developer trace for sapdbctrl.

A log file is also created during runtime for SAP Host Agent with the name sapstartsrv_ccms.log, and log files are created for RFC communication. The log files are stored in the sapccmsr subfolder of the working directory.

AL Files

For system instances, the AL* files ( ALMTTREE, ALPERFHI, and ALALERTS) are in the working directory of the SAP Host Agent. $DIR_LOGGING directory. These files contain the monitoring segment data.